The final UK troops in Afghanistan are expected to leave at the same time as US forces, which have announced they are set to pull out by 11 September.
The UK military has been in Afghanistan since 2001, with more than 450 British troops dying during the conflict with the Taliban and fighters from al-Qaeda.
The last UK combat troops left in 2014, but around 750 remain as part of the Nato mission to train Afghan forces.
Nato has repeatedly said its members will leave together.
The Ministry of Defence said any changes to the UK presence would be made in agreement with US and Nato allies and after consultation with its partners.
It said it was working closely with its allies “to support a secure and stable Afghanistan”.
“For there to be any chance of a lasting peace, the Taliban must engage meaningfully in a dialogue with the Afghan government,” it added.
US officials have said American troops will leave Afghanistan by 11 September – which will be officially announced by President Joe Biden on Wednesday.
That would coincide with the 20th anniversary of the terror attacks on the World Trade Center and the Pentagon in the US in 2001.
US Secretary of State Anthony Blinken, speaking to Nato allies in Brussels, said: “I am here to work closely with our allies, with the (Nato) secretary general, on the principle that we have established from the start: In together, adapt together and out together.”
He added that they would work closely in the coming months “on a safe, deliberate and co-ordinated withdrawal of our forces from Afghanistan”.
The new deadline is four months later than the Trump administration previously agreed in a deal with the Taliban.
Our defence correspondent Jonathan Beale says the UK, like most Nato allies, relies on the US’s infrastructure, logistics and support in Afghanistan.
The US has some 2,500 troops in the country as part of a 9,600-strong Nato mission.
At the height of the war, Nato had more than 130,000 troops from 50 nations in Afghanistan. The UK had 9,500 personnel and 137 bases in Helmand province alone.
The speaker of the Afghan parliament, Mir Rahman Rahmani, has warned that the withdrawal of foreign forces in the current circumstances would lead to civil war.
In February 2020, the US and the Taliban agreed a deal that would see the US and Nato allies withdraw all troops within 14 months if the Taliban upheld its promises, including not allowing al-Qaeda or other militants to operate in areas it controlled and proceeding with national peace talks.
Although the group stopped attacks on international forces as part of the historic agreement, it has continued to fight the Afghan government.
Last month, the Taliban threatened to resume hostilities against foreign troops still in the country on 1 May.